Extendible or adjustable stands are used in a wide variety of situations, such as a music stand whose height is adjustable, a cane of adjustable length, and so on.
The present invention has arisen in connection with a jacking system that includes a mechanical jack stand which is remotely controlled through a power unit that may be selectively attached to or detached from the mechanical jack stand.
An adjustable stand may include only two frames which are initially arranged in overlapping relationship to each other, and which are then extended longitudinally to increase the overall length of the apparatus while reducing the overlapping portions of the two frames. Extending or retracting one of two frames is not a difficult matter, as is amply demonstrated in the prior art. However, when two or more frames are to be extended, control of the action presents additional problems. This is particularly true in a jacking system where the extension or retraction of a mechanical stand is controlled remotely.